Tracking Area Update Procedure Unnecessary in
5G: Improving User Experience and Offloading
Signaling Overhead
Alaa A. R. Alsaeedy
dept. of Electrical and Computer Engineering
Colorado State University
Fort Collins, USA
alaa.alsaeedy@colostate.edu
Edwin K. P. Chong
dept. of Electrical and Computer Engineering
Colorado State University
Fort Collins, USA
edwin.chong@colostate.edu
Abstract—In Long Term Evolution (LTE) and future 5th
Generation (5G) wireless networks, the two procedures that are
essential to track and locate mobile User Equipments (UEs)
within the network are known as Tracking Area Update (TAU)
and Paging. These procedures are burdensome for both mobile
UEs and serving network—the mobile UEs and serving network
always initiate the TAU and Paging procedures, respectively.
Because of potentially very high-volume traffic and increasing
density of high-mobility UEs, the TAU/Paging procedure increases
not only the accompanied signaling overhead but also the power
consumption in the battery-limited UEs. Hence, this problem
will become even worse in future 5G networks because the
latter is expected to accommodate exceptional services, such as
supporting mission-critical systems (close-to-zero latency) and
extending battery lifetime (10 times longer).
We propose a new solution to solve this problem, named gNBbased
UE Mobility Tracking (gNB-based UeMT). This solution has
four features achieving 5G goals. First, the mobile UEs will no
longer trigger the TAU to report their location changes, giving
much more power saving with no signaling overhead. Instead,
second, the network elements, gNBs, take over the responsibility
of tracking and locating these UEs, giving always-known UE
locations. Third, the Paging procedure is markedly improved
over the conventional one, providing very fast UE reachability
with no Paging messages being sent simultaneously. Fourth, this
solution guarantees lightweight signaling overhead with very low
Paging delay. To this end, this solution adds no implementation
complexity; instead, it exploits the already existed LTE/5G
communication protocols, functions, and measurement reports.
Index Terms—tracking area update, paging, RNAU, anchorgNB,
AMF, MME, LTE, 5G